Lens Size??? at DVinfo.net

Daniel Boswell · October 21st, 2007, 09:23 PM

I have asked this question is several threads and haven gotten answer yet.

Is it 72..82???

Just bought the Letus Extreme and need to know if I need a step up/down ring.

TIA!

Justin Benn · October 21st, 2007, 10:02 PM

Doesn't this make a difference to the design? Just wondering out loud.

Jus.

Daniel Boswell · October 21st, 2007, 10:09 PM

Quote:

Originally Posted by Justin Benn

Doesn't this make a difference to the design? Just wondering out loud.

Jus.

Not sure what you mean. The Letus design?

Vaughan Wood · October 21st, 2007, 10:25 PM

77mm. pitch 0.75 mm (on lens).

Justin Benn · October 21st, 2007, 10:47 PM

Quote:

Originally Posted by Daniel Boswell

Not sure what you mean. The Letus design?

I meant, isn't there a reason why folks like P+S make different devices for your camera depending on chip size or am I missing something? Surely an imaging device designed to project light to a 1/3" capture chip will not natively work as well with a chip which is significantly bigger in area? Ie. you'd not be using the full extent of the larger chip, right?

Serena Steuart · October 21st, 2007, 11:01 PM

Quote:

Originally Posted by Daniel Boswell

Not sure what you mean. The Letus design?

The Letus website has no information about field of coverage, but I guess is designed for 1/3 inch sensors and smaller. You should ask them whether it will cover a 0.5" sensor with vignetting.

EDIT: I think there isn't a problem. The camera lens is focused at infinity using a supplementary lens to video an image on ground glass, so provided the ground glass is uniformly bright the primary lens takes care of coverage.

Steven Dempsey · October 21st, 2007, 11:27 PM

Daniel,

Where did you buy the Extreme? If it was from www.letusdirect.com then you were given a choice of 72mm or 82mm thread size. If you didn't choose one, it defaults to 72mm.

Daniel Boswell · October 21st, 2007, 11:36 PM

Quote:

Originally Posted by Steven Dempsey

Daniel,

Where did you buy the Extreme? If it was from www.letusdirect.com then you were given a choice of 72mm or 82mm thread size. If you didn't choose one, it defaults to 72mm.

Yeah..I bought it from their website and just chose 72mm not knowing what the EX was at the time. Adapter rings arent a big deal but i'd rather not use one if I don't have to.

David Koo · October 22nd, 2007, 06:15 AM

So it better to buy the Letus with 72mm or 82mm thread size?

Is it better to "step up" or "step down"?

Or maybe it doesn't matter...

Justin Benn · October 22nd, 2007, 08:21 AM

Quote:

Originally Posted by Serena Steuart

The Letus website has no information about field of coverage, but I guess is designed for 1/3 inch sensors and smaller. You should ask them whether it will cover a 0.5" sensor with vignetting.

EDIT: I think there isn't a problem. The camera lens is focused at infinity using a supplementary lens to video an image on ground glass, so provided the ground glass is uniformly bright the primary lens takes care of coverage.

I guess that makes sense. Guess I'll wait for some reports about what actually works in the field.

October 21st, 2007, 09:23 PM	#1
Daniel Boswell Major Player Join Date: May 2003 Location: Temecula, CA Posts: 189	Lens Size??? I have asked this question is several threads and haven gotten answer yet. Is it 72..82??? Just bought the Letus Extreme and need to know if I need a step up/down ring. TIA! __________________ DBoZ

October 21st, 2007, 10:02 PM	#2
Justin Benn Major Player Join Date: Oct 2006 Location: York, UK. Posts: 224	Is it designed to work with 1/2" chips? Doesn't this make a difference to the design? Just wondering out loud. Jus.

October 21st, 2007, 11:27 PM	#7
Steven Dempsey Disjecta Join Date: Apr 2004 Location: Seattle, Washington Posts: 937	Daniel, Where did you buy the Extreme? If it was from www.letusdirect.com then you were given a choice of 72mm or 82mm thread size. If you didn't choose one, it defaults to 72mm. __________________ Try my Digital Therapy: http://www.pinelakefilms.com/digital_therapy.html Films on ExposureRoom: http://exposureroom.com/members/disjecta.aspx/videos/

October 21st, 2007, 10:25 PM	#4
Vaughan Wood Major Player Join Date: Dec 2006 Location: Melbourne Australia Posts: 278	77mm. pitch 0.75 mm (on lens).

October 22nd, 2007, 06:15 AM	#9
David Koo Regular Crew Join Date: Oct 2006 Location: Cincinnati, OH Posts: 51	So it better to buy the Letus with 72mm or 82mm thread size? Is it better to "step up" or "step down"? Or maybe it doesn't matter...